Merge pull request #15557 from panyx0718/imperative

add sugar for fetching parameters and layers

paddle/fluid/imperative/layer.cc

@@ -207,7 +207,7 @@ framework::LoDTensor& VarBase::GradValue() {
 
 std::map<std::string, std::vector<VarBase*>> OpBase::ApplyGrad() {
   if (grad_op_descs_.empty() && backward_id_ <= 0) {
-    LOG(WARNING) << "op with no grad: " << op_desc_->Type();
+    VLOG(3) << "op with no grad: " << op_desc_->Type();
     return {};
   }
 

python/paddle/fluid/imperative/layers.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import collections
 import contextlib
 import sys
 import numpy as np
@@ -30,31 +31,45 @@ class Layer(core.Layer):
     def __init__(self, dtype=core.VarDesc.VarType.FP32, name=None):
         self._built = False
         self._dtype = dtype
+        self._parameters = collections.OrderedDict()
+        self._sub_layers = collections.OrderedDict()
+
+    def parameters(self, include_sublayers=True):
+        """Returns a list of Parameters from current and sub-layers.
+
+        Args:
+            include_sublayers: If true, also include the parameters from
+            sublayers.
+
+        Returns a list of Parameters.
+        """
+        ret = [p for p in self._parameters.values()]
+        if include_sublayers:
+            for l in self._sub_layers.values():
+                for p in l.parameters(include_sublayers):
+                    ret.append(p)
+        return ret
+
+    def sublayers(self, include_sublayers=True):
+        """Returns a list of sub layers.
 
-    def parameters(self):
-        params = []
-        for key in self.__dict__.keys():
-            value = self.__dict__[key]
-            if isinstance(value, framework.Parameter):
-                params.append(value)
-            elif isinstance(value, core.Layer):
-                params.extend(value.parameters())
-            elif isinstance(value, collections.Container):
-                if len(value) == 0:
-                    continue
-                if isinstance(value[0], framework.Parameter):
-                    params.extend(value)
-                elif isinstance(value[0], core.Layer):
-                    for v in value:
-                        params.extend(v.parameters())
-
-        return params
+        Args:
+            include_sublayers: If true, also include the layers from sublayers.
+
+        Returns a list of sub layers.
+        """
+        ret = [l for l in self._sub_layers.values()]
+        if include_sublayers:
+            for l in self._sub_layers.values():
+                for sub_l in l.sublayers(include_sublayers):
+                    ret.append(sub_l)
+        return ret
 
     def clear_gradients(self):
         for p in self.parameters():
             p._clear_gradient()
 
-    def _build_once(self, inputs):
+    def _build_once(self, *args):
         pass
 
     def __call__(self, *inputs):
@@ -71,6 +86,66 @@ class Layer(core.Layer):
     def backward(self, *inputs):
         raise ValueError("Layer shouldn't implement backward")
 
+    def add_sublayer(self, name, sublayer):
+        """Adds a sub Layer instance.
+
+          Added sublayer can be access like self.name.
+
+        Args:
+            name: name of this sublayer.
+            sublayer: an instance of Layer.
+        Returns:
+            the sublayer passed in.
+        """
+        assert isinstance(sublayer, core.Layer)
+        self._sub_layers[name] = sublayer
+        return sublayer
+
+    def add_parameter(self, name, parameter):
+        """Adds a Parameter instance.
+
+          Added parameter can be access like self.name.
+
+        Args:
+            name: name of this sublayer.
+            parameter: an instance of Parameter.
+        Returns:
+            the parameter passed in.
+        """
+        assert isinstance(parameter, framework.Parameter)
+        self._parameters[name] = parameter
+        return parameter
+
+    def __getattr__(self, name):
+        if name in self._parameters:
+            return self._parameters[name]
+        elif name in self._sub_layers:
+            return self._sub_layers[name]
+
+    def __setattr__(self, name, value):
+        if isinstance(value, framework.Parameter):
+            params = self.__dict__.get('_parameters', None)
+            if params is None:
+                raise ValueError(
+                    "super(YourLayer, self).__init__() should be called first")
+            params[name] = value
+        elif isinstance(value, core.Layer):
+            layers = self.__dict__.get('_sub_layers', None)
+            if layers is None:
+                raise ValueError(
+                    "super(YourLayer, self).__init__() should be called first")
+            layers[name] = value
+        else:
+            object.__setattr__(self, name, value)
+
+    def __delattr__(self, name):
+        if name in self._parameters:
+            del self._parameters[name]
+        elif name in self._sub_layers:
+            del self._sub_layers[name]
+        else:
+            object.__delattr__(self, name)
+
 
 class PyLayer(core.PyLayer):
     """Layers composed of user-defined python codes."""

python/paddle/fluid/imperative/nn.py

@@ -225,9 +225,6 @@ class FC(layers.Layer):
             act=act,
             name=name)
 
-    def parameters(self):
-        return [self._w, self._b]
-
     def _build_once(self, input):
         input_shape = input.shape
         param_shape = [
@@ -478,9 +475,6 @@ class Embedding(layers.Layer):
             dtype=self._dtype,
             is_bias=False)
 
-    def parameters(self):
-        return [self._w]
-
     def forward(self, input):
         out = self._helper.create_variable_for_type_inference(self._dtype)
         self._helper.append_op(

python/paddle/fluid/tests/unittests/test_base_layer.py

@@ -0,0 +1,82 @@
+# Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+import numpy as np
+
+import paddle.fluid as fluid
+from paddle.fluid.layer_helper import LayerHelper
+
+
+class L1(fluid.imperative.Layer):
+    def __init__(self):
+        super(L1, self).__init__()
+        self._helper = LayerHelper(
+            'MyLayer',
+            param_attr=fluid.ParamAttr(
+                initializer=fluid.initializer.Constant(value=0.1)))
+
+        self.w1 = self._helper.create_parameter(
+            attr=self._helper.param_attr,
+            shape=[2, 2],
+            dtype='float32',
+            is_bias=False)
+        self.w2 = self._helper.create_parameter(
+            attr=self._helper.param_attr,
+            shape=[2, 2],
+            dtype='float32',
+            is_bias=False)
+
+    def forward(self):
+        return self.w1 + self.w2
+
+
+class L2(fluid.imperative.Layer):
+    def __init__(self):
+        super(L2, self).__init__()
+        self.layer1 = L1()
+        self.layer2 = L1()
+
+    def forward(self):
+        return self.layer1() + self.layer2()
+
+
+class L3(fluid.imperative.Layer):
+    def __init__(self):
+        super(L3, self).__init__()
+        self.layer1 = L2()
+        self.layer2 = L2()
+
+    def forward(self):
+        return self.layer1() + self.layer2()
+
+
+class TestBaseLayer(unittest.TestCase):
+    def test_one_level(self):
+        with fluid.imperative.guard():
+            l = L1()
+            ret = l()
+            self.assertEqual(l.w1.name, "MyLayer_0.w_0")
+            self.assertEqual(l.w2.name, "MyLayer_0.w_1")
+            self.assertTrue(np.allclose(ret._numpy(), 0.2 * np.ones([2, 2])))
+
+    def test_three_level(self):
+        with fluid.imperative.guard():
+            l = L3()
+            ret = l()
+            self.assertTrue(np.allclose(ret._numpy(), 0.8 * np.ones([2, 2])))
+
+
+if __name__ == '__main__':
+    unittest.main()

python/paddle/fluid/tests/unittests/test_imperative.py

@@ -333,6 +333,18 @@ class TestImperative(unittest.TestCase):
         self.assertTrue(np.allclose(dy_out, static_out))
         self.assertTrue(np.allclose(dy_grad, static_grad))
 
+        params = mlp.parameters(True)
+        self.assertEqual("FC_0.w_0", params[0].name)
+        self.assertEqual("FC_0.b_0", params[1].name)
+        self.assertEqual("FC_1.w_0", params[2].name)
+        self.assertEqual("FC_1.b_0", params[3].name)
+        self.assertEqual(len(params), 4)
+
+        sublayers = mlp.sublayers(True)
+        self.assertEqual(mlp._fc1, sublayers[0])
+        self.assertEqual(mlp._fc2, sublayers[1])
+        self.assertEqual(len(sublayers), 2)
+
     def test_rnn(self):
         np_inp = np.array([[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0],
                            [10.0, 11.0, 12.0]])

python/paddle/fluid/tests/unittests/test_imperative_gan.py

@@ -33,9 +33,6 @@ class Discriminator(fluid.imperative.Layer):
         self._fc1 = FC(size=32, act='elu', name="d_fc1")
         self._fc2 = FC(size=1, name="d_fc2")
 
-    def parameters(self):
-        return self._fc1.parameters() + self._fc2.parameters()
-
     def forward(self, inputs):
         x = self._fc1(inputs)
         return self._fc2(x)
@@ -48,10 +45,6 @@ class Generator(fluid.imperative.Layer):
         self._fc2 = FC(size=64, act='elu', name="g_fc2")
         self._fc3 = FC(size=1, name="g_fc3")
 
-    def parameters(self):
-        return self._fc1.parameters() + self._fc2.parameters(
-        ) + self._fc3.parameters()
-
     def forward(self, inputs):
         x = self._fc1(inputs)
         x = self._fc2(x)

python/paddle/fluid/tests/unittests/test_imperative_ptb_rnn.py

@@ -75,16 +75,6 @@ class SimpleLSTMRNN(fluid.imperative.Layer):
             self.hidden_array.append(pre_hidden)
             self.cell_array.append(pre_cell)
 
-    def parameters(self):
-        parameters = list()
-        for param in self.weight_1_arr:
-            parameters.append(param)
-        for param in self.weight_2_arr:
-            parameters.append(param)
-        for bias in self.bias_arr:
-            parameters.append(bias)
-        return parameters
-
     def forward(self, input_embedding, init_hidden=None, init_cell=None):
         res = []
         for index in range(self._num_steps):
@@ -177,12 +167,6 @@ class PtbModel(fluid.imperative.Layer):
     def _build_once(self, input, label, init_hidden, init_cell):
         pass
 
-    def parameters(self):
-        parameters = self.simple_lstm_rnn.parameters() + [
-            self.softmax_weight, self.softmax_bias
-        ] + self.embedding.parameters()
-        return parameters
-
     def forward(self, input, label, init_hidden, init_cell):
 
         init_h = fluid.layers.reshape(

python/paddle/fluid/tests/unittests/test_imperative_resnet.py

@@ -21,7 +21,6 @@ import paddle
 import paddle.fluid as fluid
 from paddle.fluid import core
 from paddle.fluid.layer_helper import LayerHelper
-from paddle.fluid.optimizer import SGDOptimizer
 from paddle.fluid.imperative.nn import Conv2D, Pool2D, BatchNorm, FC
 from paddle.fluid.imperative.base import to_variable
 from test_imperative_base import new_program_scope
@@ -173,11 +172,13 @@ class ResNet(fluid.imperative.Layer):
         for block in range(len(depth)):
             shortcut = False
             for i in range(depth[block]):
-                bottleneck_block = BottleneckBlock(
-                    num_channels=num_channels,
-                    num_filters=num_filters[block],
-                    stride=2 if i == 0 and block != 0 else 1,
-                    shortcut=shortcut)
+                bottleneck_block = self.add_sublayer(
+                    'bb_%d_%d' % (block, i),
+                    BottleneckBlock(
+                        num_channels=num_channels,
+                        num_filters=num_filters[block],
+                        stride=2 if i == 0 and block != 0 else 1,
+                        shortcut=shortcut))
                 num_channels = bottleneck_block._num_channels_out
                 self.bottleneck_block_list.append(bottleneck_block)
                 shortcut = True
@@ -223,8 +224,7 @@ class TestImperativeResnet(unittest.TestCase):
                 batch_size=batch_size)
 
             dy_param_init_value = {}
-            for param in fluid.default_main_program().global_block(
-            ).all_parameters():
+            for param in resnet.parameters():
                 dy_param_init_value[param.name] = param._numpy()
 
             for batch_id, data in enumerate(train_reader()):
@@ -247,16 +247,14 @@ class TestImperativeResnet(unittest.TestCase):
                 dy_out = avg_loss._numpy()
 
                 if batch_id == 0:
-                    for param in fluid.default_main_program().global_block(
-                    ).all_parameters():
+                    for param in resnet.parameters():
                         if param.name not in dy_param_init_value:
                             dy_param_init_value[param.name] = param._numpy()
 
                 avg_loss._backward()
 
                 dy_grad_value = {}
-                for param in fluid.default_main_program().global_block(
-                ).all_parameters():
+                for param in resnet.parameters():
                     if not param.stop_gradient:
                         np_array = np.array(param._ivar._grad_ivar().value()
                                             .get_tensor())
@@ -267,8 +265,7 @@ class TestImperativeResnet(unittest.TestCase):
                 resnet.clear_gradients()
 
                 dy_param_value = {}
-                for param in fluid.default_main_program().global_block(
-                ).all_parameters():
+                for param in resnet.parameters():
                     dy_param_value[param.name] = param._numpy()
 
         with new_program_scope():
@@ -349,6 +346,7 @@ class TestImperativeResnet(unittest.TestCase):
         self.assertTrue(np.allclose(static_out, dy_out))
 
         self.assertEqual(len(dy_param_init_value), len(static_param_init_value))
+
         for key, value in six.iteritems(static_param_init_value):
             self.assertTrue(np.allclose(value, dy_param_init_value[key]))
             self.assertTrue(np.isfinite(value.all()))